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Visitors with the Clark Telescope

The Clark Telescope at Lowell Observatory


The Clark Telescope is closed for renovations from January 1, 2014 through mid-2015. Daytime Deep Space Tours will still generally go inside of the dome. In the evening, we will use the recently renovated 16-inch McAllister Telescope as our primary telescope for public viewing.

JANUARY 24, 2014 CLARK TUBE AND LENS CELL REMOVED Click here for photos. - The fair winter weather has allowed the renovation project to jump ahead of schedule and in dramatic fashion. Ralph Nye had devised the plan to move the telescope tube and lens cell to the machine shop on Mars Hill so he and colleagues could carefully disassemble, clean and repair the parts. Ralph also designed a structure to be assembled outsides and adjacent to the shop and which would support the telescope mount, allowing the crew to examine the components, including the critical main bearing that supports the several-ton weight of the telescope.

Given that work couldn't start until January 1, chances were pretty good that snow would by that time cover the ground, preventing the removal of telescope and mount until perhaps spring. However, January saw record dry conditions in Flagstaff so Ralph arranged with a crane company to remove the tube assembly and take it to the shop on January 28, while concurrently digging a 10-foot diamter, 4 -foot-deep hole and then installing cement posts held in place by cement, which would hold the mount.

After carefully reviewing and tweaking the removal plans, Ralph and crew, along with various staff and photographers, were ready when the crane arrived on the morning of the 28th at 6:30 a.m. For the next six hours, Ralph led a crew that first removed three of the six telescope counterweights, then the priceless lens cell, with 24"-diameter lens doublet in place, followed by the 15-foot long upper tube segment and, finally, the corresponding lower tube segment. The crew carefully transported the pieces to the machine shop for evaluation, repairs, and cleaning. Workers carefully lifted all of the pieces except the lens cell by the crane through the shutter doors on the dome roof. This marked the first time since 1897 that the telescope had been disassembled.

On February 20, the crane removed the massive, unwieldy mount.

Our fundraising effort, highlighted by major donations from the Toomey Foundation for the Natural Sciences. and the late Joseph N. Orr, will cover the cost of the essential restoration work. If you would like to support other Clark-related efforts, particularly for educational exhibits, please call Antoinette Beiser at (928) 233-3216.

See previous renovation updates here.

 Visitor Info


Covers day and evening programs; reservations not needed.

Adults: $12

Seniors, AAA, college students: $11

Ages 5–17: $6

Under 5: Free

Members: Free

For general questions about our day and evening programs, call the Visitor Center at (928) 233-3212 during open hours (listed below).

Groups of 15 or more are eligible for a group discount; to qualify, you must make reservations at least 3 weeks in advance. Contact Samantha Flagg by email or phone at 928-856-9484.

2015 Hours

Monday through Saturday
10 a.m. - 10 p.m.

10 a.m. - 5 p.m.

Arizona observes Mountain Standard Time year round.
Click here
for the current time in Flagstaff, AZ.

Extended Hours in 2015

Feb 15, 2015 - Open until 10 p.m.

Special Closures in 2015

Jan 1, 2015 - Closed all day

Nov 26, 2015- Closed all day

Dec 25, 2015 - Closed all day